Experimental support for the model of Bray-Liebhafsky oscillatory reaction based on the heterogeneous effects

Abstract

Recently, we developed a conceptually new model of the Bray-Liebhafsky (BL) oscillatory reaction based on specific redistribution of energy connected with the formation of a new gaseous phase in the system. The model predicts that the amplitude of concentration oscillations and their frequency are tightly connected with the total amount of oxygen in the solution, present in the form of dissolved molecules and oxygen bubbles (gas cavities). As a new conceptual approach, it needs extended experimental support for further corroboration. In this work, we developed an experimental setup for simultaneous measurement of the redox state of the system by a Pt electrode, flow of the oxygen above the reaction mixture and temperature of the solution. In this way the oscillatory evolution is correlated with the formed oxygen in the system at different mixing rates and the highly exothermic development of the oxidation branch. The obtained results give strong support for the predictions of the model and offer a new conceptual base for deeper understanding of the reaction mechanism.